Concrete mixer



Nov. 25, 1941. R. M. HOYA 2,264,039

CONCRETE MIXER Original Filed'Feb. 11, 1938 2 sheets-sheet'l NOV. 25, 1941. HQYA I 2,264,039

CONCRETE MIXER 1 Original Filed Feb. 11, 1938 2 Sheets-Sheet 2 Patented Nov. 25, 1941 UNITED STATES CONCRETE MIXER Boy M. Hoya, Milwaukee, Wis., aasignor to The T. L. Smith Company, Milwaukee, Wis., a cor p'oration oi Wisconsin Original application February 11, 1938, Serial No. 190,013. Divided and this application August 14, 1939, Serial No. 290,084

9 Claims.

This invention relates to concrete mixers and refers particularly to the so-called front end charging mixers which are those charged and discharged from the same end of the drum, the discharge being efiected by tilting the drum, and this application is a division of the copending application of Roy M. Hoya, Serial No. 90,0 filed February 11, 1938.

In charging the drums of mixers of this character, especially where they are arranged in a battery, the dry aggregate is conducted from a central hopper into the mouth of the drum through a charging chute which is mounted to swing from an operative charging position leading to the mouth of the drum to a position remote from the drum and out of the path of the drum contents spilled therefrom upon tilting of the drum.

To improve this charging operation, this invention has as one of its objects to provide a simple but efiective manner of sealing the connection between the mouth of the drum and the discharge end of the charging chute.

Still another object of this invention resides in the provision of novel means for introducing the water into th drum, which is so designed that as the water enters the mixing drum it flows around the inner surface of the drum.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed in accordance with th best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view in side elevation of two concrete mixers constructed in accordance with this invention, arranged in a battery;

Figure 2 is an enlarged side view showing the relationship of the charging chute and the mixer drum;

Figure 3 is a front view of one of the charging chutes to show particularly the seal for the juncture between the charging chute and the mouth of the mixing drum;

Figure 4 is a detail view in side elevation of the means for sealing this juncture;

taken through Figure 2 on the plane of the line 5-5, also showing in detail the manner in which the mouth of the mixing drum is sealed; and

Figure 6 is a detail sectional view taken 5 through Figure 3 on the plane of the line 6-6 to like parts, the numeral designates a central supply hopper below which two concrete mixers 6 are mounted with their front ends or mouths in position to receive the aggr ate conducted thereto by supply chutes I, and to spill. their it mixed batches into a hopper 8. The supply hopper 5 is provided with gates 9 to controlthe discharge oi. the material therefrom, and the charging chutes I are hingedly mounted at at ill from any suitable support, in position toreceive the. materials from the outlet ports of the hopper.

Water supply pipes II are also provided to conduct water into water passages l2 carried by the supply chutes and positioned to discharge the water into the mixer drums above the dryaggregate.

The two mixers comprising the battery shown are identical in construction, and consequently, a description of one will suflice for both.

The mixer is of the tilting type and has a drum I3 rotatably mounted in a cradle l4. The cradle is pivotally supported between spaced pedestals i5 set on a base IS. The drum is driven by an electric motor II supported from the tilting cradle and drivingly connected through a suit- 5 able transmission (not shown) with a ring gear tilted discharging position, as shown at the right in Figure 1, the charging chute I must be moved or swung clear of the mouth of the drum, and

to this end, a frame [9 rigidly attached to the tilting cradle has its outer end connectedwith the lower end ofth charging chute by a link 20. These parts are so proportioned that when the drum is in its mixing position, the charging chute is held in its proper charging position, and as the drum is tilted to discharge its contents,

the chute is swung clear of the mouth of the drum, as'clearly shown at the right in Figure 1.

During the charging of the mixer, it is desirable to have as close a juncture between the mouth oi. the drum and the charging chute as .Figure 5 is an enlarged cross sectional view possible. To this end, the charging chute protrudes a slight distance into the mouth of the drum, as best shown in Figure 2, and a sealing collar or ring, indicated generally by the numeral 2|, is mounted on the adjacent end of the char-ging chute to engage the edge of the drum. This sealing collar comprises two half-ring sections 22 and 22 which together comprise an annular flat ring completely encircling the discharge end of the charging chute and of a size to engage with the outer edge of the mixing drum.

The lower half-ring section 22 is mounted from the charging chute by means of an angle iron 24 extending around the lower half of the chute and securely welded or otherwise flxed thereto. The cylindrical flange 25 of this angle iron is of a size to closely flt the inner periphery of the half-ring section 22 so that regardless of its position with respect to the width of the flange 25, a clos flt will be maintained between these parts The other flat flange 26 of the angle iron 24 is bored at a plurality of spaced points for the reception of studs 21. These studs have one end secured to the half-ring section 22 and their other ends project through the holes in the flanges 26 to have tensioning nuts 20 threaded thereon. Coil springs 22 encircling the studs are conflned between the half-ring section 22 and the flange 26 to yieldingly urge the halfring section outwardly toward the discharge end of the charging chute. Consequently, when the charging chute and drum are in charging relation, the outer face of the half-ring section 22 engages the edge of the mixing drum.

Inasmuch as the drum rotates and the half-' ring section 22 is stationary, it is desirable to provide a wear plate 3| which is of the same size and shape as the half-ring section 22 and is secured thereto. by bolts for quick replacement.

The upper half-ring section 22 consists merely of a flat band shaped in the form of a half-ring with its inner periphery 7 8 closely adjacent to the upper half of the discharge chute, and like the ring section 22 is of a size to lie flat against the edge of the drum. This half-ring section 23 is resiliently mounted by means of two spring blades 3|, each anchored to one end of the lower half-ring section 22 and secured to the adjacent end portions of the upper ring section 23.

Consequently, the upper half-ring section is free to flex in the manner shown in dotted lines in Figure 4 during the motion of the charging chute toward and from the mouth of the mixing drum as the mixing drum moves through the flnal' stages of its return to normal mixing position and its initial tilting motion.

With this construction, the introduction of the solid aggregates is accomplished without objectionable leakage and without having dust blow out through the mouth of the mixing drum.

The introduction of the water into the mixing drum is eifected in such a manner that the water entering the drum swirls around the inner wall of the drum. For this purpose. the water passage i2 is mounted on the upper part of a chute in an inclined position, as best shown in Figure 3; and the lower lip 22 of its inner wall curves outwardly, as best shown in Figure 6, and has a plurality of deflecting vanes 33 connecting it with the top of the water passage.

with this arrangement, the water flowing down through the passage l2 discharges into the mixing drum at such an angle as to flow spirally over the inner wall of the mixing drum to thereby insure optimum mixing conditions.

Th drum is tilted from one position to the other by fluid pressure operated means.comprising a cylinder 34 in which apiston (not shown) reciprocates in response to the application of fluid pressure at one side or the other of the piston. The piston rod 24' which projects from one end of the cylinder is connected to the tilting cradle so that reciprocation of the piston is transmitted to the cradle to tilt the same in one direction or the other. The manner in which the fluid pressure is conducted to the cylinder 24 to effect tilting of the drum, and the way in which accidental or unintentional tilting of the mixing drum out of its mixing position is precluded constitutes the subject matter of the aforesaid copending application and will not be here described.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent to those skilled in the art that this invention eflects a substantial improvement in the construction of concrete mixers.

What I claim as my invention is:

1. In a concrete mixing apparatus having a tilting drum adapted to be charged through one end thereof, and having a movable charging chute adapted to have its discharge end projected into the mouth of the drum for charging the drum:

means for providing a seal at the juncture of the mixing drum and charging chute comprising, a flange encircling the charging chute and engageable with the end of the mixing drum, and resilient means mounting the flange for movement relatively to the charging chute and so that the flange presses against the end of the mixing drum when the charging chute and mixing drum are in charging position in response to said resilient means.

2. In a concrete mixing apparatus having a tilting drum adapted to be charged through one end thereof, and having a movable charging chute adapted to have its discharge end projected into the mouth of the drum for charging the drum: means for providing a seal at the juncture of the mixing drum and charging chute comprising, a half-ring extending substantially about the lowerhalf of the charging chute in position to engage the adjacent edge of the mixing drum with the charging chute extending slightly into the drum; yielding means mounting said half-ring and resiliently pressing the same against the end of the drum when the chute and drum are in charging relation; a second halfring extending about the remainder of the charging chute in position to engage the adjacent edge of the mixing drum; and means resiliently mounting said last named half-ring from the first mentioned half-ring.

3. In a concrete mixer having a mixing drum and a charging chute adapted to have its discharge end projected into the mouth of the drum for charging the drum: means for sealing the juncture between the charging chute and the mouth of the drum comprising a pair of independent annular half-rings, one of said annular half-rings extending about substantially one-half the circumference of the charging chute adjacent to its discharge end in position to engage the edge of the mouth of the mixing drum; means for mounting said half-ring from the charging chute for movement toward and from the discharge end of the chute and for maintaining a substantially close flt between said halt-ring and the chute; means for yieldingly urging said halfring toward the end of the chute to press the same against the edge ofthe mixing drum when the chute and mixing drum are in charging relation; the other of said half-rings encircling the remainder of the charging chute in position to engage the adjacent end of the mixing drum; and means for resiliently mounting said second halfring.

4. In a concrete mixer having a rotatable mixing drum: a charging chute for charging the drum through one end thereof, said chute having a substantially cylindrical discharge end portion and having its main portion designed for the passage of dry aggregate into the mixing drum; and a fluid passage formed on the wall of the chute so as to be a part thereof and having an inlet adjacent to the upper end of the chute for the admission of fluid and an outlet arranged to discharge fluid into the mixing drum above the dry aggregate entering the drum from the charging chute, said fluid passage having its discharge end arranged to form a substantially flat opening with the walls thereof so disposed as to dis' charge the fluid in a substantially fiat sheet against the inner wall of the drum.

5. In a concrete mixer: a rotatable drum having a single charging and discharging opening; a charging chute mounted adjacent to said opening for swinging movement to and from a charging position to direct aggregates into the drum; a closure connected with the charging chute for closing the drum opening surrounding the chute when the chute is in charging position; and a water injection nozzle carried by the charging chute on fixed relation thereto for introducing water into the interior of the drum.

6. In a concrete mixer: arotatable mixing drum having a single charging and discharging opening; a combined charging hopper and sealing door mounted adjacent to said opening for swinging movement to and from a charging position to direct dry aggregates into the drum and for sealing the opening in the drum; and a water injection passage carried by said combined charging hopper and sealing door and having its discharge end located outside the path of the dry aggregates entering the drum through the charging hopper and pointed toward the closed end of the drum.

'7. In a concrete mixer: a rotatable mixing drum of the type adapted to be charged and discharged through the same end; a charging chute movably mounted adjacent to said end of the drum for directing dry aggregates through the central portion of said end of the drum; closure means connected with said charging chute and encircling the same to engage said end of the drum and thereby close the annular portion thereof surrounding the charging chute; means for moving the connected charging chute and closure member to and from acharging position at which the closure member engages the drum; and a water passage carried by the connected charging chute and closure member so as to at all times maintain a-predetermined relationship therewith and having its discharge positioned to direct water into the drum and against a side wall thereof.

8. In a concrete mixer: a rotatable mixing drum having a single opening for'charging and discharging the drum; a chute movable toward the drum opening to a charging position for charging the drum and movable away from said opening to enable discharging of the drum, said chute being adapted to substantially close said opening when in charging position; and a water injection nozzle carried by the chute so as to at all times maintain a predetermined relation therewith and having its discharge adjacent to the upper portion of the discharge end of the chute for introducing water into the drum above the path of dry aggregates introduced into the drum through the chute.

9. In a concrete mixer: a rotatable mixing drum having an opening through which the drum is charged and discharged; a charging chute mounted for motion toward the drum opening to a predetermined charging position at which materials are directed by the chute into the interior of the mixing drum, said chute being movable away from said opening to enable discharging of the drum; and a water injection nozzle carried by the chute for motion therewith to and from its predetermined charging position and having its discharge so fixed with respect to the chute as to discharge water into the drum above the path of dry materials introduced into the drum through the charging chute.

ROY M. HOYA. 

